Device for determining local absorption values in a slice of a body, and an array of detectors for such a device.
The invention relates to a device for determining local radiation absorption values in a slice of a body, comprising at least one radiation source for generating a fan-shaped beam of radiation which irradiates the body, and an array of detectors for detecting radiation which passes through the body in various directions, the direction of the radiation being situated in the slice, the radiation source and the array of detectors being situated opposite each other on each side of a central axis through the body to be examined, the detectors on and near a connecting line between radiation source, central axis and array of detectors having a smaller detection surface area than the detectors which are situated further from the connecting line, a detector signal from a detector being electrically isolated from the detector signal from any other detector. The invention furthermore relates to an array of detectors for such a device.
A device of the described kind is known from U.S. Pat. No. 3,973,128. This patent describes a detector construction which has a spatial resolution, in the absorption distribution of the irradiated slice to be reconstructed, which is position-dependent. The detector construction comprises detectors whose detection surface areas facing the body are not equal. At the ends of the array of detectors, the detection surface areas are larger than the detection surface areas in the center of the array, with the result that the spatial resolution in the center of the reconstructed absorption distribution is higher than that at the edge.